The triple album format springs to mind career-surveying hits compilations, Zappa-type improvisations, Grateful Dead live sets or the Clash’s Sandinista! A 27-song, three-disc record of all new material is not the kind of thing you’d associate with a pop-friendly hip-hop duo that had its first hits just four years ago. Then again, most duos aren’t Rae Sremmurd. Sure, maybe Sr3mm — the ambitious third album from twin brothers Swae Lee and Slim Jxmmi — contains more songs than their entire output up to this point. But as their longtime producer Mike Will Made It pointed out last week: “They only got 26 songs before this project. Eleven or 12 of ’em are platinum.” Not bad for a couple dudes who, not too long ago, were squatting in an abandoned house in Tupelo.

Still, an hour and 40 minutes of music is a tough ask. And in the era where extra-long albums are intentionally padded to boost streaming numbers, it’s easy to feel cynical about the motives behind the sprawling Sr3mm, which is split between a disc of traditional collaborative fare and solo showcases for Swae (Swaecation) and Jxmmi (Jxmtro). But Rae Sremmurd’s rowdy, free-spirited, super-catchy songs are the perfect antidote for that cynicism; and since 2014’s less-is-more banger “No Flex Zone,” their music has grown lusher, their cadences more complex, making the leap to Sr3mm less of a stretch that it might seem. Where recent marathons like Migos’ gratuitous Culture II felt more about streaming algorithms than art, Sr3mm rarely wears out its welcome. The project’s spiritual predecessor, OutKast’s Speakerboxxx/The Love Below, marked the beginning of the end for André 3000 and Big Boi’s creative partnership; but Swae and Jxmmi’s solo turns crackle with promise — and there’s nothing matching their electricity when they’re in the zone together.

The best evidence is “Powerglide,” an ode to Swae’s slime-green Lambo that feels how the titular word sounds: so fast and smooth you’re practically flying. All cascading synths and near-liturgical vocal melodies, it’s a brilliant flip of Three 6 Mafia’s 2006 song “Side 2 Side” that invites the group’s Juicy J along for the joyride (it’s one of countless examples of the Memphis duo’s persistent influence on 2018 rap). That single aside, though, Sr3mm‘s first disc doesn’t exactly break the mold of what you’ve come to expect from Rae Sremmurd — namely, sparse, sprightly club bangers. And on tracks like the bleary-eyed “Up in My Cocina,” the duo’s yelped cadences skirt a fine line between meditative and repetitive.

All that changes with the balmy, neon-lit Swaecation, which feels like an Eighties romantic thriller set in a Los Angeles where the sun is always mid-set — a place of endless drugs and tainted love, somewhere between “Hold On We’re Going Home” and “In the Air Tonight.” Swae ditches the rapping for love-drunk melodies; “Winter’s over, let the sun in,” he chants on the chillwave-y “Lost Angels.” The moody 808s and dubious women of “What’s in Your Heart?” evoke pure Miami Vice noir; and on the dewy, reverb-drenched “Offshore,” Swae cedes the spotlight for an epic Young Thug verse in which he vows to “slap the shit out of Donald Trump.”

But perhaps Sr3mm’s biggest surprise is Jxmmi’s solo performance. In the past, he’s been out-shined by Swae’s obvious starpower, but here he swaggers and stunts; if Swaecation is sunset music, Jxmtro is the soundtrack to 4 AM bad decisions — devious, scuzzy, bass-boosted trap bangers for the after-after-afterparty. On the haunted-sounding “Chanel,” guest Pharrell sounds as though he’d been inhaling laughing gas just before stepping into the booth, and the minimalist pan flute beat of “Anti-Social Smokers Club” sounds as if it was crafted by a wasted Pied Piper. Wherever the brothers go from here — as a duo or as solo artists — it’d be wise to follow.